1. Field of the Invention
The present invention relates to a lens apparatus (lens unit) detachable from an imaging apparatus main body, the imaging apparatus main body (camera unit) from which the lens unit is detachable, and an imaging apparatus that includes the lens apparatus and the imaging apparatus main body.
2. Description of the Related Art
Recently, there has been produced a video camera that enables replacement of a lens unit. A feature of the product of this category is that a user can interchangeably use lens units of various features according to an object image to be captured. In such an interchangeable lens system, there has been discussed a system for controlling exposure. Specifically, an exposure state is detected on a camera unit side, and information for controlling a diaphragm of a lens unit side is generated on the camera unit side so that the exposure state can coincide with a predetermined value, and is transmitted to the lens unit side. The lens unit side controls the diaphragm based on the information for controlling the diaphragm, which has been received from the camera unit side (as discussed in Japanese Patent Application Laid-Open No. 3-10580).
However, in the conventional imaging apparatus, no consideration is given to the possibility that the responsiveness (light amount change per unit time) of the diaphragm, mounted in the lens unit, may be changed by the camera unit. As a result, a function of changing the responsiveness of exposure control cannot be realized.